The study was based on data from the 2006-08 National Survey of Family Growth, which attempted to measure sexual behavior, sexual attraction and sexual identity among males and females aged 15 to 44.

Of the 13,500 responses, 10 percent of women aged 22 to 44 with a bachelor's degree said they had had a same sex experience, compared with 15 percent of those with no high school diploma.

Women who had completed high school, or had some college, were somewhere in the middle.

Six percent of college-educated women reported oral sex with a same-sex partner, compared with 13 percent who did not complete high school.

"I can't say I expected it -- one of those, 'Oh, that's interesting,' and after a five-second pause, it's not that unreasonable at all kind of reaction," said Stephanie Coontz, co-chair and director of public education at the Council on Contemporary Families at the University of Illinois.

"They are much more willing to joke about it, even when they haven't done it," she said. "When you actually look at same-sex families, many are working-class and impoverished, raising kids."

According to the Williams Institute at the UCLA School of Law, more same-sex couples are raising children in economically poorer states like Arkansas, Louisiana, Mississippi and Texas than in places like California and Massachusetts.

These families defy the stereotype that mainstream gay America is white, affluent, urban and living in the Northeast or on the West Coast. They are much more socio-economically diverse, according to U.S. Census data.

Twice as Many Women as Men Have Same-Sex Experience

"A lot of these women were heterosexual and had kids in those marriages and have moved on to lesbian relationships," said Coontz. "High school dropouts live in communities where there are real shortages of good male partners. It's not surprising to me that these women are experimenting to find out if female partners would be more reliable."

The CDC report, which was released earlier this month, also showed that the gender gap in same-sex relationships was wide. Twice as many women as men reported same-sex behavior.

Three percent of the women -- and 5 percent of the least-educated women -- said they were attracted equally to men and women, compared with one percent of the men.

Even though 13 percent of all the women surveyed said they had experienced sex with another woman, the vast majority did not identify themselves as gay or bisexual.

A similar survey in 2002 showed no patterns of educational difference in women's behavior.

Camille Beredjick, a 20-year-old journalism and gender studies major at Northwestern University who describes herself as bisexual, said the report made sense to her.

"I would say women who don't have a high school degree or who come from different socioeconomic backgrounds have more sexual freedom in general," she said. "They are not tied to monogamous relationships or sex within marriage standards."

College women may also have different priorities, said Beredjick. "They might be more focused on school and career, and sex isn't necessarily what's on everyone's mind."

Beredjick said she had always resented labels like "lesbian until graduation" and "bisexual until graduation."

"It infuriates me," she said. "Honestly, everyone is a little bisexual to a different degree and college is a perfect time to explore that and see what you are into. Nothing is wrong with experimenting a bit and figuring out what you like."

Women Are More Flexible Sexually

In fact, experts say that women are more fluid in their sexuality.

Lisa Diamond, associate professor of gender studies at the University of Utah, has been studying the topic for years, and says women are, indeed, more "flexisexual" and flexible in their sexuality for a variety of cultural, and perhaps biological, reasons.

"I think there is a growing awareness of the fact that you don't have to be 100 percent gay to have the capacity to enjoy same-sex contact," said Diamond, who is author of the 2008 book, "Sexual Fluidity: Understanding Women's Love and Desire."

"In the old days, any instance of same-sex attraction was automatically put in the category of bisexual or lesbian, and now we realize women are more complicated than that," she said. "There are more examples floating around in popular culture, and the term reflects that."

Anna North, who wrote about the CDC study for the sex and celebrity website Jezebel, said, "Having same-sex experiences isn't just learned in college."

"I think the most interesting thing is it busts the stereotypes of who has these same-sex experiences that are portrayed by the media," said North. 'It's not just the girl who goes off to college and discovers her sexuality in a women's studies class."

"People in the LGBT (lesbian, gay, bisexual and transgender) community are pretty annoyed by this kind of stereotyping and we see a lot of different pop culture portrayals that make it seem like it's a male fantasy and really less about the women's actual experience -- more about what college boys like to fantasize about," she said.

Realizing that same-sex experiences transcend class may suggest more societal acceptance, according to North. "I also wonder, are the women who may not have gone to college getting more comfortable telling researchers they had same-sex experiences?"

One commenter posed this question: "Could it be that lesbians are overrepresented among high-school dropouts because they face more discrimination? That is, I wonder if the story is that women who have same-sex experiences are not graduating from high school because high school is shi**ty to LGBT kids?"

"The report highlights a fact that we've known all along: the LGBT community is very diverse," said Sharda Sekaran, spokeswoman for the advocacy group GLAAD. "We span education levels, identities and races and come from a wide array of backgrounds and communities."